Nick Reiner appears with Deputy Public Defender Kimberly Greene (not pictured) during his arraignment in Los Angeles County Superior Court in Los Angeles, California, charged with the murder of his parents, Rob Reiner and Michele Singer Reiner, in their Los Angeles home in December last year. Photo: CHRIS TORRES/Pool via REUTERS Nick Reiner, the troubled son of slain Hollywood filmmaker Rob Reiner, pleaded not guilty on Monday to murder charges stemming from the fatal stabbing of his parents in their home, one of the most shocking celebrity homicide cases in Los Angeles history.